Controls for cutting presses



June 25, 1968 D. E. BANKS ET Al. 3,389,628

CONTROLS FOR CUTTING PRESSES Filed April 15, 1966 13 Sheets-Sheet 1 June25, 1968 D. E, BANKS ET Al. 3,389,628

CONTROLS FOR CUTTING PRESSES Filed April l5, 1966 15 Sheets-Sheet 2 June25, 1968 D. E. BANKS ET AL 3,389,628

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CONTROLS FOR CUTTING PRESSES June 25, 1968 l5 Sheets-Sheet '7 FiledApril l5, 1966 June 25, 1968 D. E. BANKS ET Al. 3,389,628

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CONTROLS FOR CUTTING PRESSES Filed April l5, 1966 l5 Sheets-Sheet l0 ACDC' DC AC' 43 LEFT RIGHT D/E SEA/.sofa C//acU/r i K8 K 'A KD-B June 25,1968 D. E. BANKS ET Al.

CONTROLS FOR CUTTING PRESSES 13 Sheets-Sl'xeefI 123 Filed April l5, 1966June 25, 1968 D. E. BANKS ET AL CONTROLS FOR CUTTING PRESSES eats-Sheet13 Filed April 15, 196e lllwl |l| .l.| IW M MTN Il H L f R w T l n V1.1W @mi uw #IIJ IL" w Vllwl QUI United States Patent 3,389,628 CONTROLSFOR CUTTING PRESSES David E. Banks, Hamilton, DonaldF. Herdeg, Beverly,Ralph E. Karcher, Jr., and Abdullah A. Khambaty, Magnolia, and WilliamB. Mercaldi, Beverly, Mass., assignors to United Shoe MachineryCorporation, Boston, Mass., a corporation of New Jersey Filed Apr. 15,1966, Ser. No. 542,954 13 Claims. (Cl. 83-62) This invention relates toimprovements in cutting7 presses and more particularly `to improvementsin controls for cutting presses for dieing out parts from sheetmaterial.

The invention is illustrated as embodied in a cutting press of thetraveling head type wherein a relatively small platen is supported byyoverhead beam means for movement across a relatively wide work support,but it will be understood that the invention in many of its aspects isnot limited to presses of this type.

In dieing out parts from work pieces using die cutting presses, it is acommon procedure for the operator to position the work piece on the worksupport, `and to place, pic-k up, and replace a die on the work piece,using the cutting head after each placement to press the die through thework, until all the intended cuts have been made in that position of thework piece. After every cut, to permit the operator to pick up the cutparts and the die, the platen must be moved transversely to clear thedie and for the next cut brought .back over the die in its new position.

-Past efforts .to automate this procedure have provided means forcausing the beam or platen of a cutting press to move from a retractedor inoperative position to an operative position over the die, to pressthe die through the work and then return to the retracted position. Thismode of operation incurs a loss of time after the operator has placedthe die, which loss is the time required for the operator to move to andoperate the lcontrol Iand for the beam or platen to be moved over `thedie from its retracted position. In other words, the operator, afterplacing the die, has to move his hands, work the controls and await acomparatively large amount of time for the platen to move over the die,as well as the .times for the platen to press the die through the workand get out ofthe way, before he can pick up the die and replace it. Wehave found that substantial operating time may [be saved by la mode ofoperation in which the beam or platen, having automatically moved asideafter a cut to permit replacement of the die by the operator, isautomatically caused to return toward the next operative position. 'Inthis mode, with suitable timing of the sequence of movements, the platenwill arrive over the die immediately after the operator has iinishedreplacing it and the vertical cutting stroke may then be tripped by theoperator or by suitable automatic means without having to await thereturn transversing movement of lthe platen.

It is accordingly an object of the present invention to provide acutting press of the type having a laterally movable platen in which theplaten, after pressing the die through the work piece, is automaticallycaused to withdraw transversely of the work support to clear the die andthen return in the opposite direction for bringing the platen over thedie in its new position.

It is a further object of the present invention to provide in a cuttingpress control means whereby the transverse and vertical movements of theplaten are automated to a degree where the operator may give his fullattention to the manipulation of the die.

To these ends and in accordance with a feature of the invention, thereis provided in a cutting press of the foregoing type having a platen, awork support, means for supporting the platen for movement perpendicularto the work-engaging surface ofthe work support and transversely thereofand power means for providing said movements, in combination therewith,control means for the power means comprising (a) stroke contr-ol meanshaving tripl means actuatable for initiating movement of the platentoward the work support to press a die'there'on and stroke terminatingmeans responsive to a predetermined signal for terminating the movementof the lplaten, toward the work support and for initiating movement ofthe platen away from the work support and (b'),travelrse control meansoperative in response to said signal f or causing transverse retreatmovement of the platen to clear .the die and thereafter transversereturn movement of `said platen in the opposite direction.

In accordance with a further feature of the invention the returnmovement termination is provided by the trip means which is alsooperative for initiating the perpendicular movement of the platen'. l l

lIn accordance with still another feature of the present invention theItrip means electric signal is provided by a die sensor carried by theplaten adjacent its leading edge which is operative in response tomovement over a cutting die. In accordance with yet another lfeature ofthe present invention the control means includes a hand sensor includinga sensing element or plate carried by the platen adjacent its leadingedge which is -operative in response to sensing the proximity of aportion of lthe'body of the operator in the path of movement of theplaten to effect interruption of the return movement of .the platen.

In accordance with yet another feature of the i-nvention, the handsensor is operative for distance discrimination between two zones ofdifferent extent from a sensing plate. This control is operative inresponse to sensing the body portion of the operator in the farther zonein order to interrupt return movement of the platen. It is operative inresponse to sensing of said body portion in the nearer zone to effectmovement of the platen away from the |body portion toward itsinoperative position.

Other lfeatures and advantages of the invention will best be understoodfrom the following description taken in connection with the accompanyingdrawings in which:

FIG. 1 is a front elevation of a cutting press embody'- ing the presentinvention;

FIG. 2 is a side elevation partly in vertical section taken on lineIiI-II of PIG. 1;

FIG. 3 is a plan view partly in section of a portion of the press shownin IFIG. 1, on an enlarged scale;

FIG. 4 is Ia diagram of the hydraulic system for the press of lF'IG. 1;

lFIGS. 5A and 5B, ltogether illustrate a diagram of the electriccircuits of the control for the press of FIG. 1;

|FIG. `6 is a detailed schematic of a portion of the control indicatedin FIGS. 5A and `S'B;

FIG. 7 is a hydraulic diagram of a modification of th control means forthe press;

FIGS. A8A and 18B, together illustrate an electrical diagram of amodified control operating with the hydraulic system of FIG. 7;

FIG. 9 is an electrical diagram of a die sensor circuit;

'FIG. 10 isa chart relating to IFIGS. -8A and 81B showing the conditionof relay coils and relay contacts at different portions of a cycle ofmovement of the press;

FIG. l1 is an angular view of a sensing head comprising a portion of ahand sensor;

FIG. 12 is a vertical section of the apparatus shown in FIG. 11;

FIG. 13 is a horizontal section of the apparatus shown in FIG. lll; and

FIG. 14 is an electrical diagram of a hand sensor employing the sensinghead shown in FIG. 11.

Referring to FIGS. 1, 2 and 3, the .illustrative press comprises a frame10 carrying a work support 12 provided 3 with a conductive cutting pad13 adaptednto receive work pieces 14 for cutting into work parts bymeans of a die 16. The upper portion 18 of the frame 10 is provided withrail means 20 extending horizontally above the work support 12 forsupporting a carriage 22 on rollers 24 journaled therein.

The carriage 22 supports a bearing tube 26 in which a platen bearingcylinder 28 is vertically slidable for raising and lowering a platen 30in cutting strokes for pressing thevdie 16 through the work and againstthe pad 13. Rotation of the platen bearing cylinder is prevented by theprovision of four vertical slide tubes 32 connected at their bottom tothe platen L30 and journaled through the carriage 22. Platen returnsprings 34 extend through the slide tubes from the platen to the upperportion of the bearing tube 26 where they are secured to brackets 36-carried on a bearing tube cover 3S bolted to the tube 26. A hollowpiston rod V extends downwardly from the cover 38 and carries at itslower end a piston 42 adapted for a sliding fit with the inner surfaceof the cylinder 28.

Means comprising a flexible hydraulic hose 44, one end of which isconnected to piston rod terminal fittings 46, is provided forconnecting, through the piston rod, the chamber beneath the piston witha source of pressure fluid through a pump -48 driven by electric motor50 and iiywheel 50A so that when pressure iiuid is admitted to thechamber the platen is caused to descend against the force of the springs34 and finally the cutting force of the die 16.

Movement of the carriage to eliect movement of the platen 30transversely of the work support is provided by a traverse screw 60journaled in bearings 62 at opposite ends of the frame portion 18. Thescrew 60 has threaded engagement with a nut 64 disposed between parallelears 66 extending rearwardly of the bearing tube. The screw 60 is drivenby a reversible hydraulic motor 68.

Referring now to FIG. 4, the hydraulic system of the press comprises theelectric motor 50 and flywheel SGA driving the pump 48 for supplyinghydraulic uid to the piston 42 and cylinder 28 for providing ver-ticalmovement of the platen. The motor 50 drives .a second pump 80 forsupplying pressure fluid to the traverse motor 68. Both pumps aresupplied from a sump 82. Pressure fluid from the pump 48 is supplied tothe cylinder 28 through a conduit 84 and a solenoid valve SV1 which isopen only when the solenoid is energized. A high pressure solenoid valvecomprising a piloted discharge valve 86 and a solenoid pilot valve 88normally maintains the pressure in the conduit 84 at a minimuminoperative to effect downward movement of the platen, by dischargingthe conduit 84 to the sump unless the solenoid of the valve 88 isenergized at which time the high pressure valve closes. The pump 80provides pressure uid to the motor 68 through a conduit 90, a fast-slowsolenoid valve 92 introducing a selected one of two restrictions 94, anda right-left solenoid valve 96 having solenoids 96A and 96B controllingthe direction of transverse movement. Relief valves 98 across the motorconduits are provided to limit the motor torque, for example in theeven-t of mechanical stoppage of traversing movement, and also todynamically brake the traversing movement.

FIGS. 5A and 5B show diagrammatically the electric circuits of the presscontrol. In accordance with a feature of the invention, the controlprovides means for selecting the mode of operation of the press fromseveral modes provided which range from essentially manual to fullyautomatic through several degrees of automated cycles. The intermediatecycles are termed semi-automatic indicating that the head or platenmoves horizontally and vertically automatically, while the placing ofthe die and the removal of the work isdone manually. Circuit lines arenumbered in a column at the left while a column on the right indicatesthe lines where the contacts of the various components are located, theunderlined numbers indicating closed contact points.

The schematic of FIGS. 5A and 5B is based on symbols such as those usedby the LLC. standards, and is tied into the hydraulic circuit of FIG. 4by appropriate labels. Accordingly, reference numerals will be usedchiefly for identifying the main operating components and assemblies.

The control circuit comprises a transistorized stroke initiating andterminating control circuit 500 (line 4) of the type disclosed in UnitedStates Patent No. 3,204,506, issued Sept. 7, 1965 in the name of FrankW. Reinhold (see FIG. 6B of said patent). Briefly, the circuit shown inFIG. 6 shows how closure of contact ICR causes energization of ZCR andthe solenoidl valve 88 and shows a selector switch for selecting apredetermined stroke terminating signal from closure of a lower limitswitch or from platen to cutting pad conductivity through a die.

The circuit of FIGS. 5A and 5B includes a number of adjustable timers,e.g. 502 (line 9) which operate after closure of their operatingcontacts, e.g. 2CR (line 8) to transfer their contacts after apredetermined time period.

The circuit also includes a hand sensing relay circuit 504 (line 34)whose circuit is shown in detail in FIG. 14 and which comprises asensing head 510 (FIGS. 11, 12 and 13) carried by the platen 30 at eachlateral edge (FIG. 1). The hand sensor has a quarter wave length antennacomprising a capacity plate 512 carried by the sensing head 510 whichacts as a capacity sensor, an RF oscillator 51,4, two amplifiers 516,4518 and two switching circuits 520 and 522.

With the sensor mounted on the head, the oscillator 514 is tuned toresonance by adjusting the capacitor in its tank circuit for minimumcurrent. The antenna is then tuned to resonance hy varying the capacitor524 in its circuit for maximum current. Accordingly, any change incapacitance sensed by the plate 512 will reduce the current drawn by theoscillator. The change in oscillator current is communicated through aresistance bridge 526 to the amplifiers which are adapted to respond todifferent changes in oscillator current to effect their switchingfunction. While the detector is particularly adapted for use with amodication of the control circuit illustrated in FIGS. 8A and 8B and theschematic of FIG. 14 is tied specifically into the latter schematicsince the sensor is able to distinguish between positions of theoperators hand differently spaced from the capacitor plate, the controlis suitable for use with the circuit of FIGS. 5A and 5B where only onelevel of sensitivity is employed. It is noted that the sensor head ismounted on the carriage in an attitude such that the capacitor platedoes not sense a die carried by the work support.

The circuit of FIGS. 5A and 5B also includes a die sensor whose circuitis illustrated in FIG. 9 and which employs sensing heads 600 (FIGS. l, 2and 3) carried by the platen adjacent the leading and trailing edges andcomprising a ferrite core coextensive with said edges. The core has across section in the form of the letter E, the core being mounted withthe legs extending downward with their ends llush with the lower Surfaceof the platen. Again the schematic of FIG. 9 is tied into the controlcircuit modification of FIGS. SA and 8B, but is suitable for use in thecircuit of FIGS. 5A and 5B where it is indicated at line 64.

The mode switching system comprises a bank of single or double pole pushbutton switches interlocked so that no two buttons can be depressed atthe same time and arranged so that operation of any button willtemporarily disconnect the D.C. supply, dropping out any latched relay.

The Move-Up switch (line 10) permits application of power to thesolenoid valve SVI for moving the platen upwardly. The Move-Left switch(line 40) energizes the relay 4CR whose contacts at line 24 energize theMove- Lef solenoid of the Right-Left solenoid valve 96 and via thecontacts in line 31 energize the pilot valve 102 of the high pressurevalve 100 (FIG. 4). The Move- Right switch, line 41, providescorresponding traverse in the opposite direction through the contacts oflSCR. lA double pole 'double throw switch (lines 25 and 27) enables theoperator to select the direction in .which the heading will-moveimmediately following a cut..The upper armature is shown in themove-left-after-cut position aud, following a pause of the head in itsvinoperative position during a cycle, the move-right-after-pauseposition. Thelower armature is shown in themove-right-after-cut andmove-left-after-pause position. Mode L1:'Manual.--This mode providesforoperation of the press in which the operator, after positioning the die,positions the platen over the die using the Move- Left or"Move-Rigl1tbuttons. For this mode the operator actuates Mode l switch, thus openingline 17. The operator thentpresses the trip buttons of line 1. which,through 1CR causes Q5 (FIG. 6) to conduct and thus initiates operationof the stroke control circuit 500. The platen moves down onto the die,cuts, and then, by reason either of the die contacting .the conductivecutting-pad, or by closure of a lower limit switch, depending on theposition of a selector switch shown at lines 6 and 8, the platen movesupward. The operator then uses either one of the Move-Left or Move-Rightbuttons to move the head aside. Upward movement of the platen isdetermined by the stroke timer 502 initiated lby reclosure of the 2CRcontacts of line 8. A traverse delay timer of line 13 is also caused togo through its cycle, but is ineffective to latchv in SCR because of theopen mode switch.

Mode 2: Improved manual.-This mode, provided by actuation of the Mode 2switches, is similar to Mode l with the additional feature that when thetraverse delay timer of line 13 transfers its contact TDT (line 15), SCRlatches through its own contact in line 17 and initiates a traversetimer (line 20) causing the head to move to the side at the fast speeduntil the traverse timer times out when contacts 'IT in line 2S open.

- Mode 3: Semi-automatic (catching head on ljly) provded'by actuatingthe Mode 3 switch-After -movement ofthe platen to the side under thecontrol of the traverse timer as in Mode 2, and the opening of thecontacts TT in line 2S, a pause timer (line 37) times out closingcontacts in line23 to effect movement of the traveling head back towardthe original position of the die at the slow speed. The head willcontinue moving until the operator presses the trip switches for theAnext cut. The-operator presses a holding button to drop out relay SCR,or one ofthe limit switches is opened when the traveling head reachesthe end of its travel. v vMode 4: Semi-automatic with timed return-Forthis mode, the Mode 4 switch (line 42) is closed energizing M4CR openingcontacts in line 16 to incorporate normally closed return traversecontacts RTT of line 18 in the energizing circuit of SCR. Accordingly,when the return traverse timer of line 39 times out during returnmovement of the head, the contacts RTT draw open dropf ping out SCR andstopping the return movement.

Mode 5: Semi-automatic (die sensed only during return traverse).-Thismode is provided by. actuating the Mode 5 switch of line 45 energizingMSCR introducing into line 18 normally closed contacts of relay 9CR.Also, the die sensing selector switch of line 56 is actuated. Handsensing can be used with this mode for improved operator safety and ifrequired, actuate hand sensing selector switches ofthe hand sensor 504.In the operationof the press in this mode, after actuationof the tripswitches the platen is moved downward to cut and returned while the headmoves to the side at fast speed, pauses and returns at slow speed as inMode 3, until the die sensor headpasses over the leading edge of thedie. The die sensor relay contacts in line 56 then close, charging thecapacitor. The head continues traveling and the sensor moves over thecenter of the die beyond the sensing iield of the sensor which drops outand the normally closed die sensor contacts of line 57 connect thecharged capacitor across relay 7CR which latches in through itscontactsin line 58. 7CR also initiates a die sensordelay timer in line 62 which,after timing out, closes contacts in line 58, energizing relay 9CR whichopens normally-closed contacts in line 18, stopping the traverse motion.

Mode 6: Semi-automatic die sensed as head moves in both directions-Inthis mode the .retreat of the head, as well as the return thereof, iscontrolled by the die sensor. For this mode the Mode 6 switch, lines 44and 45, is actuated, energizing both MSCR and M6CR. MSCR incorpo.- rates9CRnormally closed contacts into line 18 while MGCR opens line-2S,changes the pause timer initiation from TT to 8CR and closes contacts inline 30. The die sensing selectorswitch of line 56 is actuated. Inoperation, after tripping, the platen is moved in its cutting stroke andafter the traverse delay timer times out contacts TDT eflfect latchingof SCR which initiates traverse movement of the traveling head. As thedie sensor passes over the leading edgeof the die, the Vdie sensor relaycloses, charging the capacitor in line 56. As the head continues, theferrite core of the sensing head 600 moves over the center of the die.At this point a smaller length of the die is withintthe magnetic field,reducing the sensing coupling to a point where the die sensor relaydrops out, this energizing relay 7CR initiating the die sensor delaytimer of line 62 which on timing out energizes relay 8CR throughcontacts in line 58. 8CR opens line S0 stopping the head and initiatesthe pause timer which times out and initiates return of the travelinghead at slow speed. This movement continues until the die sensor passesover the die, after which the return movement is stopped as in Mode 5.

Mode 7: Semi-automatic (die sensed only during return traverse and withinactive part of machine cycle occurring when the machine head s awayfrom the de).-For this mode the Mode 7 switch is actuated, energizesMSCR and M7CR.' M7CR closes contacts in line 54 and reroutes line 28 topass through 6CR normally open contacts in line 27. The pause timer isset to zero delay and the die sensing switch is actuated. The tripbuttons are pressed and the platen moves downward and upward in acutting stroke and the traveling head is moved aside as formerly at-highspeed until the traverse timer -times out, cutting olf the power fromthe traverse valves and initiating the pause timer. This timer times outand deenergizing 7CR, energizes 10CR and closesl contacts in line 28.The machine is now inactive with the head away from the die and thecircuit is conditioned so that actuation of special trip buttons (line54) will initiate one full cycle by energizing relay `6CR. 6CR thenlatches and closes contacts in line 27 effecting transverse returnmovement of the head at slow speed. The head continues until the diesensor passes over the leading end oi?.4 the die, charging the capacitorand then over `the center of the die where the die sensor drops out,latching in 7CR which initiates the die sensor delay timer. The timercloses contacts, pulling in relay `9CR which drops out SCR stopping thetraverse motion. SCR, in combination with 6CR, energizes ICR to eifect acutting stroke after which the head is moved away from the die at fastspeed as previously described.

Mode 8: Semi-automatic (die sensed as head moves in both directions andwith the machine inactive at the sde).-In this mode the Mode 8 switch isclosed, energizing MSCR, M6CR and M7CR. MSCR incorporates M9CR normallyclosed contacts in line 18; M6CR opens line 23, changes pause timeinitiation to 8CR and closes contacts in line S0; M7CR incorporates 6CRnormally open contacts in line 27 and closes contacts in line 54. Thepause time is reset to zero and the die sensing switch is actuated. Inthe operation, the regular trip buttons are pressed to cycle the machineas in Mode 7 to a condition where it is inactive with the head away fromthe die and the circuit conditions so that actuation of the special tripbuttons will initiate one full cycle. It is believed from the foregoingdescriptions that the operation of the conout detailed repetition. y

Mode 9: Full semz'automatc4 (die sensed only as'head moves toward thedie).-For` this mode the Mode 9 switch is actuated energizing MSCR andclosing the switch contacts in line 50. MSCR incorporates M9CR contactsinto line 18, the die sensing selector switch is actuated and so are thehand sensing selector switches of lines 28 and 30. In operation, uponclosing the trip switches of line 1, the platen -is moved in a cuttingstroke and after the traverse delay timer times out the traveling headis moved aside at fast speed until the traverse timer times out aspreviously described.` Then, after the pause timer times out energizingCR and closing the contacts in line 28, the head moves back toward thedie at the slow speed until the die sensor passes over the die to itscenter, energizing 7CR. 7CR initiates the die sensor delay timerenergizing 9CRXO relay, 9CRpulls in its'normally closed contacts in line18 are opened, `thus dropping out 3CR and stopping the traverse motion.Also, 7CR, SCR and `9CR are then dropped'out. 3CR, in combination withMQCR, energize lCR and the system continues to cycle until the holdbuttons are depressed. Should the operators hands be in the way of theplaten during its return traverse, the traverse motion will be stoppedby operation of the hand sensor until the path is clear. Mode 10: Fullsemi-automatic (die sensed as head moves in both drectons).-This mode isprovided by actuating the Mode 10 switch energizing MSCR, M6CR andclosing contacts in line 52. The die sensing selector switch and thehand sensing selector switches are actuated. This mode provides acontinuing cycle controlled by the die sensor which will be clear fromthe preceding descriptions of other modes. However, if the operatorshands get in the way of the return movement of the head, the traversemotion will stop until the path is clear. The operation can be stoppedby pressing the hold button.

Mode Il: Full automatic using time increments- In this mode the die-iscarried by the platen. The Mode l1 switch is actuated energizing M9CRand M11CR. In the operation of this mode, after actuation of the tripswitches, after the platen has 4moved down until stroke termination andthen up `until the stroke timer times out and sideways after thertraverse delay timer times out, the traveling head moves-to the sidefor the preset distance determined by the traverse timer. When thistimes out the con'- tacts 'IT in line 23 stop the traverse motion anddrop out SCR whose normally closed contacts in line 2 close to initiateanother stroke. l

Referring now to the modification of -the control disclosed in theschematic of FIGS. -SA and 8B, a semiautomatic mode of operation isprovided in which the head starts to move toward the die when the tripswitches 202 in line 1 are actuated and will continue to travel towardit until the die sensor has gone over the die. When the platen is overthe die, the head comes to a stop as previously described and the platenmoves down on the die and makes the cut. After the cut is made theplaten lifts up to a predetermined height, the head moves away from the4die a predetermined distance, stops there for a predetermined time andthen starts to return toward the die.

A During the above cycle when the head starts moving away after the upaction and when it has cleared the die, the operator reaches for thedie, removes the cut material and places the die in a new position.While the die is being relocated, the head may beon'the return portionof the cycle. If the operators hand is not near the die the head willcontinuato go over the die. However, if the operators hand is near thedie, but is more than a predetermined distance, for example, 7", awayfrom the sensing plate (in Zone 1 of the two-zone hand sensor), the headwill continue to travel toward the die until the distance between thehand and the plate is equal to the predeterminedI distance, i.e., 7" inthe example, then the trol toprovide the Mode 8 cycle will beapparentwithhead'will stop'. If the hand is removed the-head goes overthe die-and completes the cycle. However, if the hand is moved towardthe head and enters Zone 2 .at afse'cond predetermined distance, forexample 3" less than the Zone 1 distance, thenV the head moves away fromthe -hand a preset distance and comes to a stop. It remains there aslong as the hand in the example is more than-3" but less than v7" awayfrom it. Thus smooth operation` of the head is accomplished by providinga dead zone (here 4") Where the head stays stationary when the hand ismoved within the zone. Again, when the hand -is removed the head returnsover the die and completes the cycle, In Vthe operation of the handsensor, just asthe hand enters Zone 1, the zone which extendsfarthestfrom the capacity plate, its amplier 516 deactivates K9 in theswitch circuit 520 which, in turn, through sequencing of the Coast Timerand energizing K11, stops the'head. No further action of the head willtake place if the hand is between Zone l and Zone`2i.e., is in the deadzone, because biasing of they Zone 2 amplifier is set to deenergize theswitching circuit 522 at minimum current drawn by the-oscillator.4 Now,if the operators hand enters-Zone 2, its amplifier deactivates the Zone2 switching circuit which sequences the head to move away from the handa set distance determined by the 3".Coast Timer which would place thehand in the dead zone. When thehand is removed the oscillator becomesloaded and. draws more current, thus activates theamplifiers andswitching circuits to allow the head .to return to the die.

The Aoperation of the control circuit of FIGS.` -SA and 8B is believedto be clear from the schematic. However, a relay chart is provided inFIG. 10 to facilitate an understanding of the operation by showing theconditions of the relays and their contacts at different stages of :themachine cycle. The relay contacts shown in FIG. 10 are arranged incolumns under the functions Down, Up, Away and Return. It will beunderstood that each horizontal group under a given function representsa logic expression in Boolean algebra. Thus all the contacts under agiven function-must be closed in order for the function to be initiated,except where an or term is indicated.

Having thus described our invention, what we claim as new and desire tosecure byv Letters Patent of the United States is:

1. In a die cutting press having a work support,a platen, means forsupporting the platen for movement toward and away from the work supportand transversely thereofand power means for effecting such movements, incombination therewith, control means operatively connected to said powermeans -for causing said power means to effect cyclical movement of theplaten, said control means comprising t (a) stroke control means havingtrip means actuatable to vcause movement of the platen toward the worksupport and having stroke terminating means responsive to alpredetermined signal for interrupting said movement and for causingmovement of the platen away from said support, and (b) traverse controlmeans operative in lresponse to said predetermined signal forcausingtransverse movement ofthe platen of retreatin one direction for apredetermined distance and then of return in the opposite direction. 2.Apparatus as in claim-1in which said traverse control .meansadditionally-has means operative to interrupt the return movement oftheplaten. `3.- Apparatus as in claim 1 in which said traverse controlmeans additionally has means operative to interrupt the return movementvofthe platen after a predetermined return distance. I v t 4. Apparatusas in claim 1 in which said traverse control means additionallycomprises variable'timing means for at least one of 'saidtraverse'movements and is opera tive vto-interrupt -said one movementafter a predetermined'time'interval.

5. Apparatus as in claim 1 in which said traverse controlmeansadditionally has means operative at a predetermined position of theplaten in its path of transverse movement to interrupt the returnmovement of the platen.

6. Apparatus as in claim 1 in which said traverse c'ontrol meansadditionally includes means operative in response to actuation of saidtrip means to interrupt the return movement of the platen.

7. Apparatus as in claim 1 wherein the traverse control meansadditionally comprises means for providing a speedwof retreat greaterthan the speed of return.

8. Apparatus as in claim 1 wherein the traverse control meansadditionally comprises timing means operative to establish apredetermined variable interval between the movements of retreat andreturn.

9. Apparatus as in claim 1 wherein the traverse control means includes ahand sensor having a sensing element carried by the platen, the traversecontrol means being operative in response to movement of the elementinto predetermined proximity With a portion of a human body to interruptthe return movement of the platen.

10. Apparatus as in claim 9 wherein the traverse control is responsiveto a body portion in a iirst zone extending a given distance from thesensing element to interrupt the return movement of the platen, and isalso responsive to a body portion in a second zone extending a shorterdistance from said element to cause the platen to retreat.

11. Apparatus as in claim 1 in which said control means additionallycomprises die sensing means including a sensing element carried by theplaten, said control means being operative under the control of saidsensing means to interrupt said return movement and initiate movement ofthe platen toward the work support in response to movement of saidelement over a die as the platen passes thereover on its returnmovement.

12. Apparatus as in claim 11 in which the traverse 10 control meansadditionally includes means controlled by die sensing means in responseto movement of the platen clear of the retreat portion of the traversecycle to interrupt the movement of retreat.

13. In a die cutting press having a platen, a work support, means forsupporting the platen for movement toward and away from the work supportand'pfor movement transversely of said support, -power means forproviding said movements of the platen, in combination therewith,control means for said power means comprising means for initiatingmovement of said platen transversely of said support to a predeterminedposition to bring said platen over a die positioned on the work support,sensing means operative in response to disposition of a body portion ina zone adjacent said platen for temporarily interrupting said transversemovement of the platen until said body portion is out of said zone,means comprising a die sensor operative responsively to movement of theplaten over a die on the work support and operative at saidpredetermined position for initiating downward movement of the platentoward the work support to press said die through a work piece, stroketerminating means responsive to a predetermined electrical signal forinterrupting the movement of the V4platen toward the work support andmeans acting in response to said last signal for thereafter effectingmovement of the platen away from the work support and transverselythereof.

References Cited UNITED STATES PATENTS 2,718,260 9/1955 Oakes 83-682,929,969 3/ 1960 Denysiuk 340-258 X 3,204,506 9/ 1965 Reinhold 83-5343,212,382 10/1965 Haas 83-537 ANDREW R. JUHAsz, Primary Examiner.

13. IN A DIE CUTTING PRESS HAVING A PLATEN, A WORK SUPPORT, MEANS FORSUPPORTING THE PLATEN FOR MOVEMENT TOWARD AND AWAY FROM THE WORK SUPPORTAND FOR MOVEMENT TRANSVERSELY OF SAID SUPPORT, POWER MEANS FOR PROVIDINGSAID MOVEMENTS OF THE PLATEN, IN COMBINATION THEREWITH, CONTROL MEANSFOR SAID POWER MEANS COMPRISING MEANS FOR INITIATING MOVEMENT OF SAIDPLATEN TRANSVERSELY OF SAID SUPPORT TO A PREDETERMINED POSITION TO BRINGSAID PLATEN OVER A DIE POSITIONED ON THE WORK SUPPORT, SENSING MEANSOPERATIVE IN RESPONSE TO DISPOSITION OF A BODY PORTION IN A ZONEADJACENT SAID PLATEN FOR TEMPORARILY INTERRUPTING SAID TRANSVERSEMOVEMENT OF THE PLATEN UNTIL SAID BODY PORTION IS OUT OF SAID ZONE,MEANS COMPRISING A DIE SENSOR OPERATIVE RESPONSIVELY TO MOVEMENT OF THEPLATEN OVER A DIE ON THE WORK SUPPORT AND OPERATIVE AT SAIDPREDETERMINED POSITION FOR INITIATING DOWNWARD MOVEMENT OF THE PLATENTOWARD THE WORK SUPPORT TO PRESS SAID DIE THROUGH A WORK PIECE, STROKETERMINATING MEANS RESPONSIVE TO A PREDETERMINED ELECTRICAL SIGNAL FORINTERRUPTING THE MOVEMENT OF THE PLATEN TOWARD THE WORK SUPPORT ANDMEANS ACTING IN RESPONSE TO SAID LAST SIGNAL FOR THEREAFTER EFFECT INGMOVEMENT OF THE PLATEN AWAY FROM THE WORK SUPPORT AND TRANSVERSELYTHEREOF.